Test-Retest Reliability and Known-Groups Validity of Trunk Muscle Tests in People With Multiple Sclerosis: A Cross-Sectional, Case-Control Study

Reliability of a Trunk Flexion and Extensor Muscle Strength Test with Hand-Held and Isokinetic Dynamometers in Female Athletes

An accurate trunk muscle strength assessment seems very important to design and individualize training and rehabilitation programs in clinical and sport settings. Hand-held dynamometers (HHDs) are interesting alternatives to isokinetic dynamometers for assessing trunk isometric muscle strength because they are inexpensive instruments and easy to use. This cross-sectional observational study aimed to examine the reliability of two novel sitting tests for assessing trunk flexion and extension isometric strength using an HHD and their relationship with two other novel isometric tests that use an isokinetic dynamometer. Twenty-four female amateur athletes (age: 24.5 ± 2.64 years; body height: 164.45 ± 6.33 cm; body mass: 63.17 ± 10.35 kg) participated in this study. A test-retest design was carried out one-week apart to examine the reliability. The relationship and the degree of agreement between the HHD and the isokinetic dynamometer measurements were analysed using Pearson correlation and Bland-Altman analysis, respectively. In general, the reliability of all isometric strength tests was good, with ICCs ranging from 0.65 to 0.87 and typical error < 15%. Pearson correlations were moderate, with values of r = 0.47 (R2 = 0.22) and r = 0.42 (R2 = 0.18) for flexion and extension strength, respectively. Bland-Altman plots showed no agreement between HHDs and isokinetic measurements. All trunk isometric tests using both, an isokinetic dynamometer and HHDs, provide reliable measurements for assessing trunk flexion and extension strength. According to the comparative analysis, both measurement types are different and cannot be used interchangeably. Health and sport professionals should choose the test that best suits the biomechanical characteristics required for functional goals or success in a given sport.

Smartphone accelerometry for quantifying core stability and developing exercise training progressions in people with multiple sclerosis

BACKGROUND

Core stability exercise programs have become popular in recent years for preserving balance and functional independence in people with multiple sclerosis (PwMS); however, their real impact is not well-known as the main intervention target (i.e., core stability) theoretically responsible for balance or functional improvements is not measured. The objective of this study was to test the reliability of accelerometers integrated into smartphones for quantifying core stability and developing exercise progressions in PwMS.

METHODS

Twenty participants with MS [age: 47.5±8.0 years; height: 1.62±0.07 m; mass: 63.4±10.9 kg; EDSS: 3.0 (1.5-6)] participated voluntarily in this study. CS was assessed in different variations of the front, side, and back bridges and bird-dog exercises by measuring the mean lumbopelvic acceleration in two testing sessions, separated by one week. Relative and absolute reliability of lumbopelvic acceleration of those exercise variations performed by more than 60% of the participants was analyzed by the intraclass correlation coefficient (ICC_3,1), and the standard error of measurement (SEM) and the minimal detectable change (MDC), respectively. Repeated measures ANOVAs were performed to detect a potential learning effect between test-retest assessments. Statistical significance was set at p < 0.05.

RESULTS

Reliability analyses revealed that good to excellent relative and absolute scores (0.85<ICC<0.96; 7.8%≤SEM≤19.2%; 21.6%≤MDC≤53.2%) for the mean lumbopelvic acceleration obtained during 10 of the 12 CS exercise variations performed by more than 60% of the participants. A non-significant between-session learning effect was detected in all the variables considered (all p values >0.05).

CONCLUSION

Smartphone accelerometry seems a low cost, portable and easy-to-use tool to objectively and reliably track core stability changes in PwMS through. However, in spite of the popularity of bridging and bird-dog exercises, only the short and long bridges and the three-point bird-dog positions proved feasible for most participants. Overall, this study provides useful information to evaluate and guide the prescription of core stability exercise programs in PwMS with mild-to-moderate impairment.

Is there a relationship between respiratory function and trunk control and functional mobility in patients with relapsing-remitting multiple sclerosis?

OBJECTIVE

Multiple sclerosis (MS) causes impairment of respiratory function, trunk control, and functional mobility. The purpose of this study was to investigate the relationship between functional mobility and respiratory function and trunk control in MS patients and to compare the findings with those in healthy individuals.

METHODS

Thirty MS patients and 30 healthy subjects were included in this case-control study. All participants were evaluated with a pulmonary function test, maximal inspiratory and expiratory pressure (MIP, MEP), core stability tests, a lumbopelvic stability test (LST), a 2-minute walk test (2MWT), and the Timed Up and Go test (TUG). The disability level of the MS patients was assessed with the Expanded Disability Status Scale (EDSS).

RESULTS

Respiratory function, respiratory muscle strength, trunk control, and functional mobility were lower in the MS patients than in the controls (p < 0.05). TUG values had a significant negative correlation and the 2MWT values had a significant positive correlation with MEP, core stability tests, and the LST (p < 0.05). Of the variance in the 2MWT distance, 69% was explained by the LST, EDSS, and MEP; of the variance in TUG time, 40% was explained by the EDSS and MEP (p < 0.05).

CONCLUSIONS

To preserve and develop functional mobility in MS patients, approaches to increase respiratory function and trunk control should be included in rehabilitation programs.

CLINICALTRIALS.GOV REGISTRATION NUMBER

NCT03826095.

Functional Performance, Leg Muscle Strength, and Core Muscle Endurance in Multiple Sclerosis Patients With Mild Disability: A Cross-Sectional Study

This study aimed to investigate the relationship of sit-to-stand and walking performance with leg muscle strength and core muscle endurance in people with multiple sclerosis (PwMS) with mild disabilities. In this study, 49 PwMS (Expanded Disability Status Scale score = 1.59 ± 0.79) and 26 healthy controls were enrolled. The functional performances, including sit-to-stand and walking performances, were evaluated with the five-repetition sit-to-stand test, timed up and go test, and 6-min walking test. The PwMS finished significantly slower five-repetition sit-to-stand, timed up and go, and 6-min walking test than the healthy controls. In addition, the significant contributors were the weakest trunk lateral flexor endurance for five-repetition sit-to-stand; the Expanded Disability Status Scale score, and the weakest hip adductor muscle for timed up and go; the weakest hip extensor muscles strength for 6-min walking test. The functional performances in PwMS, even with mild disabilities, were lower compared with healthy controls. Decreases in both leg muscle strength and core muscle endurance are associated with lower functional performance in PwMS.

The effects of supervised versus home Pilates-based core stability training on lower extremity muscle strength and postural sway in people with multiple sclerosis

BACKGROUND

Pilates-based core stability training (PBCST) is a controlled form of exercise that may improve the transmission of torque from the upper extremities and trunk to the lower extremities by enabling the core muscles to activate effectively.

OBJECTIVES

The aim of this study was to investigate the effects of PBCST given as supervised or home-based on lower extremity strength and postural control in multiple sclerosis.

METHODS

Fifty individuals were enrolled and randomly allocated into two groups. Primary outcome measures were knee muscle strength and postural sway in different conditions. The supervised group received PBCST 2 days per week for 8 weeks at the clinic, and the other group performed PBCST at home. Exercises were progressed every 2 weeks in both groups.

RESULTS

Between groups, the supervised group was mostly superior to the home group (p < 0.05). A significant improvement was noted in all parameters in both groups, except some sub-parameters of postural sway in home PBCST (p < 0.05).

CONCLUSIONS

Supervised PBCST was determined to be more effective than home PBCST in improving strength, postural control, core stability, physical capacity, and fatigue. Although supervised training is the primary choice, home training can be recommended to patients who have limitations attending supervised sessions.